Successors to Donovan already being considered?

Labor Secretary Raymond J. Donovan returns to his Labor Department office this week after a trip abroad, but it may be only a question of time before he gives it up.

For months, Mr. Donovan has weathered a barrage of charges that he consorted with organized crime figures and made payoffs to union officials before his appointment to the Cabinet.

Now, there is speculation within the Labor Department and Congress that the secretary will resign or request a leave of absence within the next two or three weeks. With resignation a possibility, a so-called ''routine'' list of seven potential successors has been drawn up. Anson Franklin, a White House spokesman, says he cannot confirm the existence of such a list. But others say that it is not unusual to consider in advance possible successors if it appears that an official may leave office.

Secretary Donovan continues to proclaim his innocence and to express confidence that, in time, a special prosecutor's investigation will clear him. A report on the investigation is expected to be in the hands of the President within a few weeks.

According to Mr. Franklin and others, the President shares Secretary Donovan's confidence of vindication and is not likely to call for his resignation.

But pressures are building in Congress. Not only Democrats but also a number of key Republicans feel Donovan should resign. Even if he is innocent, they argue, his effectiveness as a Cabinet member has been compromised until it is near zero. Most Labor Department decisions and policy matters are being left to subordinates.

A few days before Senate Democrats wrote the President asking that Donovan take a leave of absence, Sen. Orrin G. Hatch (R) of Utah said that it will be ''only a matter of time,'' in his opinion, before Donovan resigns to devote all of his time and energies to clearing his reputation.

Although Undersecretary of Labor Malcolm R. Lovell Jr. says speculation about a resignation is ''premature, improper, and unfair'' many in the Labor Department say privately that they feel Donovan should step down.

Mr. Lovell, the No. 2 man, is credited with running the department while Donovan concentrates on his defense. He is high on the list of those reportedly under consideration as possible successors.

Others reported to be on the list include W. J. Usery, a former labor secretary and a onetime trade unionist who would have solid labor backing; Betty Southard Murphy, former chairman of the National Labor Relations Board, also supported by unions; Assistant Labor Secretary Thorne Auchter; Robert F. Bonitati, President Reagan's liaison with organized labor; William E. Brock, the President's special trade ambassador; and Richard F. Schubert, a former undersecretary of labor and vice-chairman of Bethelehem Steel.

Those on the list have refused to speculate on their appointment. Says Mr. Bonitati, ''We have a sitting secretary. It is inappropriate to speculate about a list of successors.''